1. Field
The subject matter disclosed herein relates to electronic devices, and more particularly to methods and apparatuses for use in providing location related information to a mobile station.
2. Information
GPS and other like satellite positioning systems have enabled navigation services for mobile handsets in outdoor environments. Since satellite signals may not be always be reliably received and/or acquired in an indoor environment, different techniques may be employed to enable position estimation and related navigation services. For example, mobile stations can typically obtain a position fix by measuring ranges to three or more terrestrial radio transmitters which are positioned at known locations. Such ranges may be measured, for example, by obtaining a MAC ID address from signals received from such access points and measuring one or more characteristics of signals received from such access points such as, for example, signal strength, round trip delay, just to name a few examples.
By way of additional example, a mobile station, such as, a mobile phone, smart phone, etc., may perform signal-based position estimation to identify its location within a structure by considering different types of location related information. For example, expected signal data (e.g., heat map or radio map information) may be considered along with signal strength measurements, such as, received signal strength indicator (RSSI) values for signals received from various radio transmitters (e.g., access points, beacons, etc.). In other examples, expected signal data (e.g., delay map information) may be considered along with signal propagation time measurements, such as, round-trip time (RTT) values for signals exchanged with various radio transmitters. In still other instances, other types of location related information may be considered, such as, connectivity graph information, routing graph information, probability map information, and/or the like, which may relate to position points distributed in relationship to a map or graph of an indoor space. Thus, for example, a mobile station may use all or part of such location related information to estimate a relative position within the indoor space and/or to otherwise navigate therein.
Such location related information may be provided to a mobile station by one or more computing devices (e.g., servers, etc.), e.g., over wireless communication links. Such location related information may be provided for each radio transmitter and each position point within an indoor space. Accordingly, location related information may at times represent a significantly large amount of data. Transmitting such a large amount of data over a wireless network to a mobile station may prove costly in terms of power, bandwidth, and latency. Additionally, such location related information may also consume a significant amount of memory at a mobile station. Further still, a user experience with position estimation and other like location based service capabilities provided by a mobile station may be significantly affected should significant communication and/or processing delays arise, e.g., specifically with respect to a time to first fix (TTFF).